The impact of surgical approach on short- and long-term outcomes after rectal cancer resection in elderly patients: a national cancer database propensity score matched comparison of robotic, laparoscopic, and open approaches.

BACKGROUND: Elderly patients are underrepresented in studies demonstrating the advantages of laparoscopy for the management of colorectal diseases. Moreover, few studies have examined the robotic approach in this population. In this retrospective analysis, we compare outcomes for open, laparoscopic, and robotic approaches in elderly patients with nonmetastatic rectal cancer.

METHODS: The U.S. National Cancer Database was queried for patients aged ≥ 65 with nonmetastatic adenocarcinoma of the rectum who underwent surgical resection from 2010 to 2016. Groups were separated based on approach (open, laparoscopic, robotic). One-to-one nearest neighbor propensity score matching (PSM) ± 1% caliper was performed across surgical approach cohorts to balance potential confounding covariates. Kaplan-Meier estimation and Cox-proportional hazards regression were used to analyze the primary outcome of survival. Secondary outcomes were analyzed by way of logistic regression.

RESULTS: Inclusion criteria and PSM identified 1891 patients per approach (n = 5673). PSM provided adequate discrimination between cohorts (0.6 < AUC < 0.8), and potential confounding covariates did not significantly differ (respective P > 0.05). After PSM, robotic and laparoscopic approaches were associated with decreased odds of 90 day mortality compared to the open approach (P < 0.05). Compared to laparoscopy, a robotic approach was associated with increased odds of ≥ 12 regional lymph nodes examined and negative circumferential resection margin (P < 0.05). No differences were seen in 30 day or 90 day mortality between robotic and laparoscopic approaches. Cox proportional hazards regression showed that both robotic and laparoscopic approaches were significantly associated with decreased mortality hazards relative to open.

CONCLUSION: Our study demonstrates that in elderly patients, minimally invasive surgery for rectal adenocarcinoma was associated with equivalent or improved short- and long-term mortality over open surgery. Compared to laparoscopy, the robotic approach showed no survival disadvantage and greater odds of an appropriate oncological resection. Our study adds evidence to the conclusion that robotic rectal surgery can be safely performed in patients regardless of age.